The present invention relates to a sealing device for a container, making it possible to preserve the product contained in said container from contact with the ambient air or from soiling with a foreign body originating from outside the container.
This container may in particular be a xe2x80x9ctubexe2x80x9d, that is to say an envelope one longitudinal end of which has a neck and the other longitudinal end of which is closed by squeezing and assembling, particularly by welding, the walls of this envelope.
The product may be any product which it is important be protected against contact with the air or against dirt, particularly a cosmetic product, a food product or a product for medical use.
The invention also relates to a sealing device for a container as a structure of a container intended to contain two substances separately and to allow these substances to mix at the time of their use.
International (PCT) application No. WO 97/47531 describes a sealing device comprising a cylindrical part intended to be inserted in the neck of a container and two ducts for the flow of the product contained in this container. Said cylindrical part comprises a groove giving it the shape of a xe2x80x9cdiaboloxe2x80x9d and is covered with an elastomer diaphragm which hugs it closely. This diaphragm, through its elastic deformation as a result of pressure on the container, allows the product to flow out between it and said cylindrical part, and is pressed against this cylindrical part in the absence of such pressure, which means that it acts like a valve.
This device is satisfactory in practice but does, however, have the disadvantage of entailing that the shapes of said cylindrical part and of said diaphragm exactly complement each other, failing which sealing is not obtained. This complementing of shapes entails recourse to overmolding techniques which are relatively complicated to implement.
In addition, it is not precluded for there to be a space between said cylindrical part and the diaphragm, in which space a quantity of product may stagnate. This quantity of product may be contaminated with air to a greater or lesser extent, and this is not desirable in the case of a cosmetic product, a food product or products for medical use. The stopper described in this same prior international application is not suitable to every type of container, and this is a certain impediment in practice.
Document GB-A-214 548 describes a sealing diaphragm which has to be stretched out to be placed over a sealing bearing surface with which it is intended to collaborate. This stretching leads to significant difficulties in the manufacture of the container.
Document WO 98/14387 describes a sealing membrane of cylindrical shape placed over a sealing bearing surface of corresponding cylindrical shape and housed thereon by means of the engagement of an annular projection secured to the diaphragm in a groove formed in said sealing bearing surface. Aside from the difficulties in fitting it, the seal obtained does not seem to be perfect.
Furthermore, an existing container generally comprises a screw-on stopper, which, although affording the product contained in the container good protection is, on the other hand, relatively difficult to manufacture and handle. Other containers have flip-up lids, which are easier to manufacture and to manipulate than screw-on stoppers but which would not perfectly protect the product contained in the container from air or dirt.
The object of the present invention is to provide a diaphragm-type sealing device of the aforementioned type which is easier to manufacture, by means of a molding technique which is relatively simple and inexpensive to perform, making it possible to obtain a perfect seal and which can be suited to any type of container, particularly those which have caps fitted onto their neck.
Another object of the invention is to effectively dispense with the risk of contamination by the ambient air or of soiling with foreign bodies, with the quantity of product that can stagnate between the product outlet orifice from the container and the diaphragm that forms the diaphragm.
The device comprises, in a way known per se, a diaphragm valve consisting of a part forming the valve seat, in which part a duct for the flow of the product contained in the container is made, and of a diaphragm made of elastically deformable material fitted closely over this seat-forming part; this diaphragm, through elastic deformation, the result of pressure exerted on the product contained in the container allows this product to flow out between it and the seat-forming part, and in the absence of such pressure, presses against this seat-forming part to shut off the flow of product and close the container in a sealed manner.
According to the invention,
said seat-forming part has a conical or cylindro-conical overall shape and has a cross section which increases toward the orifice via which the product flows out of said valve;
said diaphragm has a conical or cylindro-conical overall shape corresponding to that of said seat-forming part, this shape being such that this diaphragm can be fitted closely onto or into this seat-forming part, and
said diaphragm and said container comprise respective bearing means collaborating with one another when the sealing device is mounted on the container so as to hold the diaphragm in its position of close fitting onto or into said seat-forming part.
Thus, according to the invention, said seat-forming part and said diaphragm can be produced independently of one another then assembled together by push-fitting to constitute the sealing device; said bearing means of the diaphragm with respect to the container therefore allow the diaphragm to be immobilized axially with respect to the seat-forming part.
This seat-forming part and this diaphragm can therefore be manufactured using molding techniques which are relatively conventional and simple to operate, and the sealing device according to the invention is no longer, as it was in the prior art, dependent on a close fitting engagement into the neck of the bottle.
The seat-forming part and the diaphragm are advantageously shaped to allow the diaphragm to be stretched out circumferentially slightly over the seat-forming part or to allow this diaphragm to be contracted circumferentially slightly in the seat-forming part, in said position of close fitting.
This circumferential stretching or this circumferential shrinking make it possible to absorb any respective dimensional variations in the seat-forming part and in the diaphragm as a result of the tolerances on the manufacture thereof.
Said bearing means may advantageously extend over the entire circumference of the diaphragm and be shaped to be able to constitute a seal between the part of the container forming the product reservoir and the neck of the container and/or between this neck and a part such as a cap that the end of the container may take.
According to a preferred embodiment of the invention, the seat-forming part is molded with a part, particularly a cap, intended to be mounted, for example by snap-fastening, on the neck of the container.
Advantageously, in this case,
the diaphragm comprises a bulge which, when said part is fitted onto the container, bears against a bearing surface formed in the neck of the container, and/or
the diaphragm has a collar projecting radially outward and shaped so that, when said part is fitted onto the container, it is gripped between the neck and this part.
Advantageously, the seat-forming part has a rib projecting from its wall, radially and toward the outside thereof, this rib being situated between the duct via which the product can be introduced between the seat-forming part and the diaphragm and the duct via which this product escapes from between this seat-forming part and this diaphragm toward the outlet orifice, the two orifices of these ducts situated closest to each other being formed near this rib.
Said rib thus collaborates with the diaphragm to form a linear seal that markedly separates the region between these two orifices and this region is reduced to a minimum. This seal acts as an effective barrier against the ingress of a foreign body, and there is practically no product that can stagnate between said orifices and can therefore become contaminated with ambient air.
As a preference, the sealing device comprises a flip-up lid shaped to be normally returned to the closed position and to pivot to the open position only under the pressure of the stream of product.
This lid completes the sealing of the container, particularly allows the quantity of product immediately to the rear of the product outlet orifice to be ensured of complete protection.
Advantageously, in this case, the lid comprises a tab shaped to, in the closed position of this lid, bear against a thickened part of the diaphragm and, when the lid is pivoted into the open position, to deform this thickened part elastically so that the latter, by elastic return, tends to return the lid to the closed position.
This thickened part may in particular belong to the aforementioned bearing means.
Said tab may comprise a catch engaging with a corresponding rim, so as to allow the lid to be mounted, the coming of this tab against said thickened part of the diaphragm holding this catch against this rim.
The lid may also comprise at least one deformable part molded integrally with it, and which is shaped to deform when the lid is brought into the open position and to tend, by elastic return, normally to return this lid to the closed position.
According to another aspect of the invention, the device comprises a cap which delimits a flow duct for the product and a lid received in pivoting on the cap to allow the duct to be closed; the cap has a hole and comprises a part made of elastic material situated inside it, facing this hole; the lid comprises a tab sized to be engaged in this hole with the possibility of clearance, this clearance allowing said lid to move between its open and closed positions; the tab further comprises a rib which can be snap-fitted behind an edge of the lid delimiting said hole, so as to allow the lid to be mounted on the cap; the assembly is shaped in such a way that when said rib is snap-fastened behind said edge, the tab deforms said elastic part so that the elastic return of this part allows the lid to be kept in its closed position and without the flexibility of this part impeding the pivoting of this lid into the open position under the pressure of the product contained in the container.
The lid is thus normally kept in the closed position, and pivots into the open position only to allow product contained in the container to flow out. This results in perfect protection of this product, and the device remains simple and easy to manufacture and easy to assemble.
As a preference, the lid comprises, on the opposite side to said tab, at least one deformable part molded integrally with it, while the cap comprises at least one corresponding wall against which this deformable part can slide when the lid is brought into the open position; said corresponding wall makes it possible to deform said deformable part in such a way that this deformation tends, by elastic return of the material of the lid, to return this lid to the closed position.
Advantageously, the cap comprises a recess for accommodating the lid in the closed position, this recess having dimensions which correspond to those of the lid and being shaped in such a way that the exterior face of the lid is in the continuation of the exterior face of the cap when the lid is in place in said recess, in the closed position.
The lid therefore offers no external grip which might allow it to be lifted. The product is thereby protected all the more vigorously.
The lid advantageously, on its exterior side and facing said tab, has a region shaped so as not to correspond precisely to the shape of the corresponding region of the cap with which engages when the lid is mounted on the cap.
The result of this is that the lid is slightly deformed elastically when the tab is engaged in said hole in the cap and that this deformation continues to normally keep the lid in its closed position.